Of known pool chlorinating devices, one comprises a vessel with a hold portion for the chlorinated water; perforated (or porous) supporting means located over the hold portion and for supporting a solid chemical chlorinating substance; and water supply means for directing at least one jet of water on to the supporting means.
The chlorinated water so produced is left inside the vessel until it is fed into the pool, so that the dissolved solid chemical substances precipitate and form deposits inside the vessel. Since the solid chemical substances normally comprise calcium hypochlorite, the deposits mainly formed inside the vessel are calcium sulphate and calcium carbonate.
Known pool chlorinating devices therefore require regular manual removal of such deposits, after first shutting down the device and so interrupting the water treatment. While the chlorinating device is turned off to clean the vessel, pool hygiene is therefore impaired; and the need for relatively frequent manual cleaning of the vessel results in relatively high maintenance costs.
U.S. Pat. No. 5,928,608 discloses a chlorinating device comprising a vessel with a hold portion for the chlorinated water and a mechanical stirrer for stirring the water contained in the hold portion. It should be pointed out that the mechanical stirrer is relatively cumbersome, expensive and difficult to implement. Moreover, since it is likely that, in use, chemical substances precipitate on the mechanical stirrer, the device disclosed by U.S. Pat. No. 5,928,608 requires relatively frequent cleaning operations.